class Math {
    @log
    add(a, b) {
      return a + b;
    }
  }
  
  function log(target, name, aa) {
      console.log(aa)
    var oldValue = aa.value;
  
    aa.value = function() {
      console.log(`Calling "${name}" with`, arguments);
      return oldValue.apply(null, arguments);
    };
  
    return aa;
  }
  
  const math = new Math();
  
  // passed parameters should get logged now
  export default math.add(2, 4);